Cap squadron size, limit replenishment rate.

This caps squadrons to 12 pilots and limits their replenishment rate to
1 pilot per turn. Should probably make those values configurable, but
they aren't currently.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1136

game/game.py

@@ -327,11 +327,14 @@ class Game:
         # one hop ahead. ControlPoint.process_turn handles unit deliveries.
         self.transfers.perform_transfers()
 
-        # Needs to happen *before* planning transfers so we don't cancel the
+        # Needs to happen *before* planning transfers so we don't cancel them.
         self.reset_ato()
         for control_point in self.theater.controlpoints:
             control_point.process_turn(self)
 
+        self.blue_air_wing.replenish()
+        self.red_air_wing.replenish()
+
         if not skipped and self.turn > 1:
             for cp in self.theater.player_points():
                 cp.base.affect_strength(+PLAYER_BASE_STRENGTH_RECOVERY)